The 33-year-old Dumervil, who logged nine sacks over the last two seasons, will join an increasingly intimidating group of rushers in California. Opposing offenses will now have to consider Dumervil, 2017 first-round pick Solomon Thomas, 2016 first-round pick DeForest Buckner and 2015 first-round pick Arik Armstead.

At the least, Lynch has a good idea of what Dumervil is capable of. The two played together in Denver for two seasons.

While adding a rotational passing-down rusher seems like a move more appropriate for a playoff contender, Lynch has three valuable rushers that need a mentor.

Alongside linebacker NaVorro Bowman, the defense has undergone a major upgrade in the professionalism department this offseason. Dumervil has been to the Pro Bowl five times, most recently after a 17-sack season in Baltimore three years ago. He missed half the season in 2016 due to off-and-on foot problems.